1. Field
The present invention relates to an assembly information management apparatus to manage a set of assembly information constituted by a plurality of parts, and an assembly information management method.
2. Description of Related Art
When representing a three-dimensional model in a three-dimensional CAD system, the three-dimensional model consists of a group of files having shape data like parts models constituting the three-dimensional model, and a file controlling the group of files and having no shape data in itself. The files having shape data are called “parts” and the files having no shape data are called “assembly information.” That is, assembly information does not refer to each part but instead refers to a unit of a plurality of assembled parts.
A designer changes shapes of parts while coordinating with peripheral parts in the course of design. In this case, regarding peripheral parts, outline shape information of three-dimensional models having assembly information, which is called “box information,” as a structural unit is acquired from a system in which each piece of assembly information is registered before conducting a search. Then a search is conducted on the system using the acquired box information to obtain peripheral three-dimensional models acquired as assembly information by the search.
As a technology regarding interference checks of three-dimensional models, a technology can be considered that determines whether boundaries of parts interfere with each other by moving models of parts using a three-dimensional CAD (Computer Aided Design) system and, if interference occurs, stops further movement of the parts and controls the parts so that the parts are not in intersecting states, and displays the parts on a monitor.
Also a technology can be considered that determines whether or not an interference check was performed in the past, excludes parts models that were not changed from check targets and outputs interference check results in the past for such excluded models.
When a part constituting assembly information is edited in a three-dimensional CAD system, the updated assembly information constituted by the edited part is stored by saving the edited part. Then, calculation of new box information of three-dimensional models having the assembly information as a structural unit is triggered by the saving.
If, for example, a part edited from one piece of assembly information is also a part constituting another piece of assembly information, new box information of three-dimensional models having the one piece of assembly information as a structural unit can be obtained by saving the one piece of assembly information, as described above.
However, because no editing is done in the other piece of assembly information, the edited part is not saved in the other piece of assembly information. Therefore, box information of three-dimensional models having the other piece of assembly information as a structural unit is not updated even after a common part shared with the one piece of assembly information is updated.
Thus, regarding the other piece of assembly information, box information used for a search remains in a state before a common part is updated even if the three-dimensional geometric model is in an updated state and thus, the three-dimensional geometric model does not correspond to the box information. Therefore, even if a search is conducted using box information as a cue, a desired search result cannot be obtained, causing a problem in design work.
If interference checks with peripheral assembly information are attempted to be performed using geometric models, it will take a very long time to file check out the geometric models due to an enormous amount of data. Thus, file checkout work can be made more efficient by using outline shape data such as box information, but if the box information does not correspond with the latest geometric model, there is a problem that an error occurs in an interference check itself.